If Zhūn has appeared in your reading, the book is naming the difficulty proper to birth. The character itself depicts a sprout bending under the weight of the soil above it. Something has begun. It has not yet found its way out.

The lower trigram Thunder is movement; the upper trigram Water is the abyss into which that movement is rising. Cloud and thunder gather but no rain has fallen. The pressure is real. The form for releasing it has not yet been built. Classical commentary places this hexagram third in the sequence precisely because, after Heaven and Earth, the first thing that happens is confusion.

What the book counsels is not advance but the appointing of helpers — 利建侯, fit to install princes. The work is structural: who will hold which part, where will the lines of responsibility run, what shape will the new endeavour take. Force the move now and the sprout snaps. Build the trellis and the climb becomes possible.

Zhūn is followed in the sequence by Méng, Youthful Folly — the unformed thing once it has come into the world and discovered it does not yet know what it is. The pair frames the entire problem of beginnings: first the difficulty of breaking ground, then the difficulty of finding your bearings once you have.